During yesterday’s World Wide Developers Conference in San Francisco, Apple didn’t make much mention of AT&T, the iPhone’s sole carrier in the US. Was it a sign of bad blood between the two companies? Perhaps. An even more likely possibility is the fact that carrier has little plan to implement some of the newly announced features for the iPhone 3.0 software.
Apparently AT&T won’t support the long-awaited addition of MMS upon the iPhone 3GS’s launch. Boy Genius Report explains the situation thusly,

[T]he reason it’s not good to go right away is because AT&T has to manually remove all the “Opt Out MMS codes” on each account. Basically, if we were to summarize this, and we’re going out a little bit of a limb, remove the Opt Out MMS code, and MMS will work with the final OS 3.0 build right away. Who wants to try it with the GM 3.0 build just released?

Also expected to be crippled at launch is the ability to tether a PC to the phone, though the company is reportedly working on a $70/month data plan that includes tether–but not SMS or MMS.